It is known that a pattern of a plurality of stripes, each of which is different in color from the neighbouring ones, can be formed on a surface of a sheet material, such as a fabric or plastic film or sheet, by using an apparatus which comprises a pair of means for feeding a sheet material into the apparatus and for delivering the sheet material from the apparatus; a coating table arranged between the sheet material-feeding means and the sheet material-delivering means and having a horizontal, smooth upper surface along which the sheet material slides; a substantially vertical coating doctor knife having a blade which is formed in a lower end portion thereof and located above the coating table, and; a coating liquid-feeding device connected to the doctor knife and having a plurality of separate compartments through which a plurality of coating liquids are concurrently fed onto a surface of the sheet material. Each of the separate compartments is defined by a pair of vertical, rectangular partitioning plates which are placed upright and above the horizontal surface of the coating table, which are spaced from each other, in parallel to each other, and which are connected to each other by an inclined guide plate. A side edge of each partitioning plate is positioned in close contact with a surface of the doctor knife, at a right angle to the surface of the doctor knife. This side edge has a lowermost end positioned at the same level as that of a lowermost end of the blade of the doctor knife. The inclined guide plate is interposed between a pair of the partitioning plates and has an upper surface which obliquely-downwardly approaches the blade of the doctor knife. The lower end of the guide plate is spaced from the blade of the doctor knife and is located above the bottom edges of the partitioning plates. The bottom edge surface of each vertical, rectangular partitioning plate is oriented so that it is not parallel to the horizontal surface of the coating table.
When the above-mentioned apparatus is used, a sheet material is continuously moved from the sheet material-feeding means to the sheet material delivering means along the horizontal surface of the coating table, and the doctor knife and the coating liquid-feeding device are placed on the sheet material. During the coating operation, by using the above-mentioned apparatus, friction is created between the upper surface of the sheet material and the bottom edge surfaces of the partitioning plates, and between the lower surface of the sheet material and the horizontal upper surface of the coating table, which causes a tension to be created on the sheet material. However, the above-mentioned frictions are not only unevenly distributed on the sheet material, but also, irregularly vary during the coating operation. Uneven distribution and irregular variation of the friction on the sheet material result in uneven distribution of tension on the sheet material and in irregular variation of the tension during the coating operation. The uneven distribution and irregular variation of the tension on the sheet material causes the thickness of the layer of each coating liquid applied onto the surface of the sheet material to be uneven in distribution and to irregularly vary during the coating operation. Also, the sharpness of both side edge lines of each of the stripes formed by the coating liquids becomes poor. Furthermore, the uneven and irregularly varying tension on the sheet material causes the sheet material to become wrinkled during the coating operation.
Accordingly, it is strongly desired to elminate the above-mentioned disadvantages from the conventional apparatus.